Handheld tissue sample extraction device

ABSTRACT

A handheld device for extracting tissue samples includes a needle arrangement and control arrangement. The needle arrangement has a cutting needle, a sample extraction needle, and a first end for inserting into tissue. The cutting needle has a cutting edge for cutting the tissue sample. The sample extraction needle has a side opening for receiving the tissue. The control arrangement has a vacuum chamber in fluid communication with the sample extraction needle. The vacuum chamber has a first member and a second member that move relative to each other. The first member is mechanically connected to the cutting needle. The handheld device is configured so that movement between the first and second members to increase volume of the vacuum chamber thereby reduces pressure in the sample extraction needle, induces movement between the cutting needle and the sample extraction needle to expose the side opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 14/357,082, filed May 8, 2014 as a national phase entry of PCT application PCT/DK2012/050412, filed Nov. 9, 2012, said application claiming priority to Denmark application PA 2011 00876.9, filed Nov. 9, 2011 and Denmark application PA 2012 00085 30, filed Jan. 30, 2012, all of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a handheld device for extracting tissue samples from tissue.

BACKGROUND OF THE INVENTION

It is known to extract tissue samples from tissue using various devices. Such a device is described in US patent application US 2007/106176 A1.

However, there may be several problems associated with such known devices. It is therefore an object of the invention to provide a simple yet efficient handheld device for extraction of tissue samples.

BRIEF DESCRIPTION OF THE INVENTION

The invention relates to a handheld device for extraction of tissue samples, comprising a needle arrangement and a control arrangement,

said needle arrangement comprising a cutting needle and a sample extraction needle,

said needle arrangement having a first end for inserting into tissue,

said cutting needle comprising a cutting edge for cutting said tissue sample from said tissue,

said sample extraction needle comprising a side opening for receiving said tissue,

said control arrangement comprising a vacuum chamber in fluid communication with said sample extraction needle,

the vacuum chamber comprising a first member and a second member,

said first and second members being adapted to move relative to each other,

wherein said first member is mechanically connected to said cutting needle, and

wherein said handheld device is configured so that

-   -   a movement between said first member and said second member to         increase the volume of said vacuum chamber thereby reducing the         pressure in said sample extraction needle

induces

-   -   a movement between said cutting needle and said sample         extraction needle to expose said side opening of said sample         extraction needle.

An advantage of the invention may be that by said first member and said cutting needle being connected, a minimum of driving force arrangement is required for operating said handheld device. I.e. only one driving arrangement is required to move the first member and the cutting needle collectively.

Furthermore, an important advantage of the invention may be that by moving said cutting needle along said longitudinal axis away from said sample extraction needle end and thereby exposing the side opening of the sample extraction needle, the vacuum chamber expands due to the first member being connected to the cutting needle. Therefore, and since the vacuum chamber is in fluid communication with the needle, the expanding vacuum chamber, having a decreasing pressure, facilitates suction of tissue in the vicinity of the side opening of the sample extraction needle into the tissue sample chamber. Thereby, the handheld device and the tissue are ready for the cutting needle to cut the tissue sample from the tissue, which may be performed by said cutting needle moving back over said side opening.

A further advantage of the invention may be that by reducing the pressure in the vacuum chamber being in fluid communication with the sample extraction needle while exposing the side opening of the sample extraction needle, a vacuum assisted handheld device is obtained, i.e. a handheld device which uses vacuum to suck tissue into the sample extraction needle which may then subsequently be cut off to give a tissue sample.

Thereby, a simple yet efficient handheld device for extracting tissue samples, i.e. for performing biopsies, is obtained.

In the present context it should be understood that side opening is an opening in the side of the inner sample extraction needle allowing a part of surrounding tissue to move through said side opening into a tissue receiving chamber of the sample extraction needle. This movement of the tissue into the tissue receiving chamber is facilitated at least partly by the vacuum in the vacuum chamber being in fluid communication with said needle arrangement, and more specifically with the tissue sample chamber of the sample extraction needle. Thereby, a vacuum assisted process for extraction of tissue sample is achieved by means of said handheld device.

It is to be understood in relation to the above that the cutting edge of the cutting needle is adapted for cutting through tissue, i.e. to separate the tissue in the tissue sample chamber from the rest of the surrounding tissue by cutting it off, thereby obtaining a tissue sample.

In the present context, said sample extraction needle is hollow so as to facilitate vacuum from the control arrangement to the tissue sample chamber and the side opening. Also, the cutting needle and the sample extraction needle both have openings corresponding to each other thereby facilitating the transfer of vacuum from the vacuum chamber to the tissue sample chamber and the side opening.

It is to be understood that the control arrangement typically may be a handle comprising a vacuum chamber and arrangements for controlling the movement of the cutting needle and for controlling the vacuum chamber. However, of course the control arrangement may be designed in various other ways allowing control of the cutting needle and the vacuum chamber.

According to an embodiment of the invention, the cutting needle is an outer needle surrounding the sample extraction needle along at least a part of the length of the cutting needle and/or the inner sample extraction needle.

According to an embodiment of the invention, said first member is connected to said cutting needle so as to increase the volume of said vacuum chamber and expose said side opening when moving said cutting needle along the longitudinal axis of the needle arrangement away from said first end of said needle arrangement.

According to an embodiment, said first and second members are adapted to move relative to each other so as to increase the volume of said vacuum chamber with a movement of said cutting needle relative to said sample extraction needle in a direction away from said first end of said needle arrangement thereby exposing said side opening of said sample extraction needle.

According to an embodiment, said handheld device is configured so that a movement between said cutting needle and said sample extraction needle to expose said side opening of said sample extraction needle is coupled to a movement between said first member and said second member to increase the volume of said vacuum chamber, thereby reducing the pressure in said sample extraction needle due to said first member being mechanically connected to said cutting needle.

According to an embodiment of the invention, said first member is a piston and said second member is a cylinder.

According to the above embodiment, the piston is mechanically connected to the cutting needle, thereby coupling the movement of the two together. Preferably the piston and the cutting needle are connected such that they move together along the longitudinal axis of the needle arrangement, but may rotates freely about the same longitudinal axis relative to each other.

According to an embodiment of the invention, said first member is a cylinder and said second member is a piston.

According to the above embodiment, the cylinder is mechanically connected to the cutting needle, thereby coupling the movement of the two together. Preferably the cylinder and the cutting needle are connected such that they move together in the direction along the longitudinal axis of the needle arrangement, but may rotate freely about the same longitudinal axis relative to each other.

According to an embodiment of the invention, said movement between said first member and said second member to increase the volume of said vacuum chamber is in a direction along the longitudinal axis of the needle arrangement.

According to an embodiment of the invention, said first member is fixated to said cutting needle.

According to the above embodiment, the first member is fixated to the cutting needle, i.e. mechanically fixated. In some embodiments the fixation is in the direction parallel to the longitudinal axis of the needle arrangement, i.e. the first member and the cutting needle will move together in this direction, but the two may rotate about the longitudinal axis independently of each other. However, in other embodiments, the two may be totally fixated to each other for every direction of movement and rotation.

According to an embodiment of the invention, the vacuum chamber surrounds at least a part of said needle arrangement.

Thereby, the fluid communication between from the vacuum chamber to the sample extraction needle may be facilitated in a simple and efficient way, e.g. by means of through-holes and/or slits in the cutting needle and in the sample extraction needle.

According to an embodiment of the invention, the vacuum chamber is centered about the longitudinal axis of the needle arrangement.

According to an embodiment of the invention, the cutting needle is an outer needle surrounding the sample extraction needle being an inner needle.

In the context of the above embodiment it is to be understood that by said cutting needle surrounding said sample extraction needle is meant that may surround the sample extraction needle or a part thereof depending on the relative position of the two. According to an embodiment, it may be understood that the outer cutting needle may be referred to as a cannula, where inner sample extraction needle may be referred to as e.g. a trocar needle or a trocar-like needle.

According to an embodiment of the invention, the relative movement of said first and second members are driven by second driving arrangement.

According to an embodiment of the invention, said second driving arrangement comprise a second spring.

In relation to the above embodiment the second spring may extend from a part of the first member and a part of the second member. Thereby, it facilitates relative movement between the two members. In embodiments where e.g. the first member is a piston and the second member is a cylinder, the second spring may be fitted to the piston near the end the piston facing away from the first end of the needle arrangement, while the second end of the second spring may be fitted to the end of the cylinder facing towards the first end of the needle arrangement. Preferably, then the spring is a compressing spring, i.e. it is compressed when the piston is fully inserted into the cylinder, and is less compressed when the piston is moved as far as possible out of the cylinder. Therefore, the second driving arrangement is preferably a spring that can be compressed or stretched, i.e. potential energy can be stored in the spring and converted into kinetic energy when released, e.g. by the movement of pins to release one or more parts affected by the biasing force of the spring, thereby initiating movement driven by the spring.

According to an embodiment of the invention, said cutting needle has a bevelled end.

An advantage of the above embodiment is that the cutting needle may have improved cutting characteristics, e.g. when performing an oscillatory rotation during cutting.

According to an embodiment of the invention, said vacuum chamber is adapted to build up a vacuum before the side opening is exposed.

An advantage of the above embodiment is that immediately when the side opening starts being just partly exposed, there is already a vacuum in the vacuum chamber, resulting in the tissue immediately being sucked into the tissue sample chamber.

According to an embodiment of the invention, said second member is adapted to perform a movement along the longitudinal axis of the needle arrangement towards the first end of the needle arrangement thereby increasing the volume of the vacuum chamber and building up a vacuum before the side opening is exposed.

In relation to the above it is to be understood that said second member may be a piston or a cylinder depending on the nature of the first member, such that the first and second members together constitute are a piston and a cylinder.

According to an embodiment of the invention, said handheld device comprises first driving arrangement for driving a movement of said second member along the longitudinal axis of the needle arrangement towards the first end of the needle arrangement.

According to an embodiment of the invention, said first driving arrangement comprise a first spring.

In relation to the above embodiment, it may in some embodiments be preferred that the first spring is connected to the second member and a casing of the control arrangement. Thereby, the first spring may move the second member towards the first end of the needle arrangement over at least some distance without moving said first member. Furthermore, when moving said second member towards the first end of the needle arrangement causes the first member to move along due to e.g. a coupling between the two members preventing them from moving out of contact with each other, the first spring may facilitate movement of the two members together relative to the rest of the control arrangement. Therefore, the first driving arrangement is preferably a spring that can be compressed or stretched, i.e. potential energy can be stored in the spring and converted into kinetic energy when released, e.g. by the movement of pins to release one or more parts affected by the biasing force of the spring, thereby initiating movement driven by the spring.

According to an embodiment of the invention, said first and second members are adapted to move together in a direction along the longitudinal axis of the needle arrangement in a direction towards the first end of the needle arrangement while being substantially stationary relative to each other,

wherein said cutting needle connected to said first member and said sample extraction needle are adapted for moving relative to each other along the longitudinal axis of said needle arrangement from a first to a second relative position,

wherein at least a part of said side opening is exposed in said first relative position, and

wherein said side opening of said sample extraction needle is substantially covered in said second relative position,

thereby cutting said tissue sample from said tissue.

An advantage of the above embodiment is by moving said first and second members together the volume of the vacuum chamber is substantially constant while the cutting needle moves over the sample extraction needle and performs a cutting action by cutting tissue extending through the side opening into the tissue sample chamber from the rest of the tissue to give a tissue sample. Thereby, the suction in the inner sample extraction needle, which sucks a part of the surrounding tissue into the sample extraction chamber, and which is facilitated by the vacuum chamber is substantially constant through the cutting process.

According to an embodiment of the invention, said movement from said first relative position to said second relative position comprises an oscillatory rotation of said cutting needle relative to said sample extraction needle about the longitudinal axis of the needle arrangement, where said oscillatory rotation comprises at least a first relative rotation and a second relative rotation, where the first and second relative rotations have different oscillatory velocities.

In the present context of the above embodiment, said oscillatory rotation is to be a rotation at different oscillatory velocities, e.g. different oscillatory velocities for the same velocity of the cutting needle between said first and second relative positions. In various examples the two different oscillation velocities may or may not be in opposite rotational direction, e.g. in one example embodiment the two rotational velocities may be in the same rotational direction, but at various numerical values of the velocities, while in another example embodiment one of the rotational velocities may be zero, i.e. the cutting needle rotates only for a portion of the way between said first and second relative positions.

According to an embodiment of the invention, said movement from said first relative position to said second relative position comprises an oscillatory rotation of said cutting needle relative to said sample extraction needle about the longitudinal axis of the needle arrangement, where said oscillatory rotation comprises at least a first relative rotation and a second relative rotation, where the first and second relative rotations have opposite rotational directions.

In the present context of the above embodiment, said oscillatory rotation is to be understood as a rotation about the longitudinal axis of the needle arrangement. Moreover, it is to be understood as a rotation that changes rotational direction at least once and possibly several times, e.g. by switching rotational direction for each 360° rotation or for each 180°, 90°, 45°, or 20° of rotation or by other angular intervals.

An advantage of the above embodiment is that by said cutting needle performing a oscillatory rotation when moving from said first and to said second relative position, the tissue cutting efficiency of the cutting edge of the cutting needle is substantially increased compared to a non-rotating cutting needle, while at the same performing said oscillatory rotation having one or more rotations in each rotational direction about said longitudinal axis of the needle arrangement so that the net sum of these one or more rotations in each rotational direction is small compared to the sum of the numeric rotations, preferably such that the net sum of the rotations is less than 360°, such as less than 180°, such as less than 90°, such as less than 45°, such as less than 20°.

A further advantage of the invention is that since the cutting needle has a net sum of rotations being much smaller compared to the sum of the numeric rotations, it is avoided that the cutting needle winds up part of the tissue or other parts of material inside the body of the person from whom this tissue sample is extracted, such as a tendon. Such winding up of the e.g. tissue or a tendon may be extremely painful and may furthermore cause the cutting needle to be stuck in the person. Thereby a less painful sample extraction can be performed by the easy-to-use handheld device.

According to an embodiment of the invention, the handheld device comprises vacuum removal arrangement for removing the vacuum when said cutting needle has reached the second relative position thereby substantially covering said side opening of said sample extraction needle.

By removing the vacuum when the cutting needle covers the side opening of the sample extraction needle, it is avoided that the tissue sample which has now been cut from the tissue moves to much up the inner space of the sample extraction needle. According to an embodiment of the invention, the vacuum removal arrangement comprises a valve.

According to and embodiment of the invention, the valve may e.g. be positioned such that it removes the vacuum by bringing the vacuum chamber into fluid contact with the surrounding, e.g. when said second member reaches a position closest to the first end of the needle arrangement, i.e. when the cutting needle has moved back over the side opening.

According to an embodiment of the invention, the control arrangement furthermore comprises a charging arrangement for charging said first and second driving arrangements.

According to an embodiment of the invention, the charging arrangement is a ring and a string.

In embodiments where the first and second driving arrangements are a first and second spring, the charging arrangement may e.g. comprise a ring and a string connected to the ring and to the first and/or second members such that when pulling the ring the first and second members move to their positions bringing the first and second springs into compressed or stretched mode, i.e. storing energy for the sample extraction sequence in the springs. Alternatively, the charging arrangement may comprise a trigger, which can be operated by one or more fingers of the user of the handheld device, to activate one or more times in order to store sufficiently energy in the driving arrangements, such as the springs. Yet another alternative solution may comprise an electrically driven motor, preferably connected to a battery, which can bring the driving arrangements, such as the springs, into loaded mode.

According to an embodiment of the invention, the sample extraction needle may be removed from the rest of the handheld device so as to remove extracted tissue samples.

Alternative, the tissue samples may be removed by other means, e.g. to an internal tissue sample storage chamber inside the control arrangement or by removing the entire needle arrangement from the tissue and extracting the tissue sample through the side opening of the sample extraction needle.

The invention furthermore relates to a handheld device for extraction of tissue samples, comprising a needle arrangement and control arrangement,

said needle arrangement comprising a cutting needle and a sample extraction needle,

said needle arrangement having a first end for inserting into tissue,

said cutting needle comprising a cutting edge for cutting said tissue sample from said tissue,

said sample extraction needle comprising a side opening for receiving said tissue,

wherein said cutting needle and said sample extraction needle are adapted for moving relative to each other in a direction along the longitudinal axis of the needle arrangement from a first to a second relative position,

wherein at least a part of said side opening is exposed in said first relative position, and

wherein said side opening of said sample extraction needle is substantially covered in said second relative position, and

wherein said movement from said first relative position to said second relative position comprises an oscillatory rotation of said cutting needle relative to said sample extraction needle about the longitudinal axis of the needle arrangement, where said oscillatory rotation comprises a first relative rotation and a second relative rotation, where the first and second relative rotations have different oscillatory velocities.

In the present context of the above embodiment, said oscillatory rotation is to be a rotation at different oscillatory velocities, e.g. different oscillatory velocities for the same velocity of the cutting needle between said first and second relative positions. In various examples the two different oscillation velocities may or may not be in opposite rotational direction, e.g. in one example embodiment the two rotational velocities may be in the same rotational direction, but at various numerical values of the velocities, while in another example embodiment one of the rotational velocities may be zero, i.e. the cutting needle rotates only for a portion of the way between said first and second relative positions.

According to an embodiment of the invention, the first and second relative rotations have opposite rotational directions.

In the present context, said oscillatory rotation is to be understood as a rotation about the longitudinal axis of the needle arrangement. Moreover, it is to be understood as a rotation that changes rotational direction at least once and possibly several times, e.g. by switching rotational direction for each 360° rotation or for each 180°, 90°, 45°, or 20° of rotation or by other angular intervals.

An advantage of the invention is that by said cutting needle performing a oscillatory rotation when moving from said first and to said second relative position, the tissue cutting efficiency of the cutting edge of the cutting needle is substantially increased compared to a non-rotating cutting needle, while at the same performing said oscillatory rotation having one or more rotations in each rotational direction about said longitudinal axis of the needle arrangement so that the net sum of these one or more rotations in each rotational direction is small compared to the sum of the numeric rotations, preferably such that the net sum of the rotations is less than 360°, such as less than 180°, such as less than 90°, such as less than 45°, such as less than 20°.

A further advantage of the invention is that since the cutting needle has a net sum of rotations being much smaller compared to the sum of the numeric rotations, it is avoided that the cutting needle winds up part of the tissue or tendon or other parts of material inside the body of the person from whom this tissue sample is extracted. Such winding up of the e.g. tissue or tendon may be extremely painful and may furthermore cause the cutting needle to be stuck in the person. Thereby a less painful sample extraction can be performed by the easy-to-use handheld device.

According to an embodiment of the invention, the oscillation control arrangement may comprise an oscillating ridge connected to e.g. the cutting needle and controlled by two pins on the control arrangement. Of course the ridge may also be on the control arrangement and the pins connected to the cutting needle. In another embodiment, the oscillation control arrangement may comprise an oscillating channel in which a pin is guided along. The channel may then be a part of the control arrangement, while the pin may be connected to the cutting needle, or opposite.

According to an embodiment of the invention, the above described handheld device may be combined with any other embodiments of the invention.

FIGURES

The invention will now be described with reference to the drawings, where

FIG. 1 illustrates a handheld device according to an embodiment of the invention,

FIG. 2 illustrates a handheld device according to an embodiment of the invention,

FIG. 3 illustrates a handheld device according to an embodiment of the invention,

FIG. 4 illustrates a handheld device according to an embodiment of the invention,

FIG. 5 illustrates a handheld device according to an embodiment of the invention,

FIG. 6 illustrates oscillation control arrangement according to an embodiment of the invention,

FIGS. 7A and 7B illustrate a tissue sample being extracted from tissue according to an embodiment of the invention, and

FIG. 8 illustrates pin control arrangements according to an embodiment of the invention.

DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a handheld device 1 for extraction of tissue samples 27 is illustrated in a cross-sectional view according to an embodiment of the invention. The handheld device 1 comprises control arrangement 2 and a needle arrangement 25. The needle arrangement 25 comprises an inner sample extraction needle 3 and an outer cutting needle 4. The inner sample extraction needle 3 has an outer diameter corresponding to the inner diameter of the outer cutting needle 4 so that the two may move relative to each other in a direction along a longitudinal axis 29 of the needle arrangement 25. The inner sample extraction needle 3 comprises a side opening 5 into a tissue sample chamber 26 and a beveled needle end 10. The outer cutting needle 4 has a cutting edge 23, which may be beveled as in FIG. 1, or may in alternative embodiments constitute an orthogonal cut-through of the outer cutting needle 4. The control arrangement 2 comprises a vacuum chamber 24, which comprises a piston 9 and a cylinder 8. The control arrangement 2 furthermore comprises a first spring 6 and a second spring 7 for supplying driving force for movement of the piston 9 and the cylinder 8. The springs 6, 7 are compression springs. The control arrangement 2 furthermore comprises a first pin 12, a second pin 13, a third pin 14, and a fourth pin 15 for controlling the movement of the piston 9 and the cylinder 8. Finally, the control arrangement 2 comprises a start button 17 for initiating the tissue sample extraction as will be described in relation to FIGS. 1-5. During use of the handheld device 1 for extraction of tissue samples 27, the needle arrangement 5 is inserted into the tissue 30 in this configuration.

The inner sample extraction needle 3 is connected to a handle 19 at the end opposite the beveled needle end 10. The outer cutting needle 4 is connected to oscillation control arrangement 11, which is connected to the piston 9 by a first connection arrangement 16. The vacuum chamber 24 is in fluid communication with the inner sample extraction needle 3, by means of e.g. openings in the outer cutting needle 4 and the inner sample extraction needle 3. Such openings may e.g. be slits positioned such that the fluid communication is upheld for any position and orientation of the outer cutting needle 4 and of the inner sample extraction needle 3 during a sampled extraction cycle. In the configuration that is illustrated on FIG. 1, the first and second springs 6, 7 are in a tensioned mode, i.e. they are compressed on the direction parallel to the longitudinal direction of the spring relative to their equilibrium position. The tissue sample extraction cycle is initiated by pressing the start button 17, which causes the cylinder 8 to be released by pins (not shown) and to move along towards the first end of the control arrangement 2 until it meets the first and second pins 12, 13. Thereby, a vacuum is build up in the vacuum chamber 24. This situation is illustrated on FIG. 2 in a cross-sectional view, where the start button 17 is pushed into the control arrangement 2 and the cylinder 8 has moved into contact with the first and second pins 12, 13.

Now, due to the pressure exerted by the cylinder 8 on the first and second pins 12, 13, the third and fourth pins 14, 15 are released, and the piston is free to move backwards, i.e. away from the beveled needle end 10 and towards the handle 19. The driving force for this movement is supplied by the second spring 7, which expands towards its equilibrium length. During this movement of the piston 9, the cylinder 8 is stationary, and the relative movement of the piston 9 and cylinder 8 away from each other expands the volume of the vacuum chamber 24, which results in a lower pressure in the vacuum chamber 24 and a suction in the needle arrangement 25. Furthermore, the outer cutting needle 4 moves with the piston 9, which means that the outer cutting needle 4 moves backwards relative to the inner sample extraction needle 3, thereby exposing and uncovering the side opening 5 of the inner sample extraction needle 3. Therefore, during this movement, the tissue sample chamber 26 is exposed, while the vacuum in the vacuum chamber 24 is gradually increased at the same time, causing soft material such as tissue 30 to be sucked into the tissue sample chamber 26. When this movement of the piston 9 and the outer cutting needle 4 driven by the expansion of the second spring 7 is completed, the configuration illustrated in a cross-sectional view on FIG. 3 is reached.

Now, the soft material such as tissue 30 surrounding the front end of the needle arrangement 25 extends through the side opening 5 into the tissue sample chamber 26. The first and second pins 12, 13 are retracted so as to release the cylinder 8. Due to the elastic driving force of the compressed first spring 6, the cylinder moves towards the beveled need end 10 of the control arrangement 2. Now, although the piston 9 is free to move back and forth in the cylinder 8, the piston 9 cannot leave the cylinder 8, e.g. due to an narrowing inner diameter of the cylinder 8 near its opening and a circular protrusion on the outside of the piston 9 near the end closest to the beveled needle end 10. Therefore, when the cylinder 8 moves towards the beveled needle end 10, the piston 9 and therefore also the outer cutting needle 4 moves with the cylinder 8, i.e. the piston 9 and cylinder 8 are stationary relative to each other, which again means that the vacuum in the vacuum chamber 24 is constant or at least substantially unaffected by the above described movement. Furthermore, the outer cutting needle 4 is connected and fixated to oscillation control arrangement 11, which move with the outer cutting needle 4 both for movements in a direction parallel to the longitudinal axis of the needle arrangement 25 and for rotations about the longitudinal axis 29 of the needle arrangement 25. The oscillation control arrangement 11 comprise on the outside a protruding ridge 20, which extends overall in a direction of the longitudinal axis 29 but which also rotates around the longitudinal axis 29 back and forth along the direction of the longitudinal axis 29. Thereby, the handheld device 1 reaches a configuration as shown in a cross-sectional view on FIG. 4.

The above described oscillation control arrangement 11 can be seen in a cross-sectional view on FIG. 6, where the oscillating ridge 20 can be seen to rotate in twice a first and twice in a second direction about the longitudinal axis 29 of the needle arrangement 25. Also, it can be seen on FIG. 6 that the net sum of the rotations is approximately zero, since the ridge 20 has the approximate same angular position in one end as the opposite end without rotating a fully around the longitudinal axis 29. In an example the ridge 20 may rotate e.g. 20° in a one direction about the longitudinal axis 29, then 20° in the opposite direction and then repeat this sequence once. In such an example, which may be close to the illustration on FIG. 6, the net sum of the rotations is substantially smaller than the sum of the numeric rotations, since the net sum is zero, while the sum of the numeric rotations is 80°. Furthermore, it can be seen on FIG. 6 that when the oscillation control arrangement 11 moves in a direction along the longitudinal axis 29 of the needle arrangement 25, the ridge 20 moves through a slit formed by a first protrusion 21 and a second protrusion 22. Therefore, during this movement, the first and second protrusions 21, 22 will force the oscillation control arrangement 11 to rotate about the longitudinal axis 29 of the needle arrangement 25, thereby facilitating an oscillatory rotation of the cutting needle 4, when it moves in a direction along the longitudinal axis 29 of the needle arrangement 25 due to the cutting needle 4 being connected and fixated to the oscillation control arrangement 11.

Now, referring to FIG. 5, the handheld device 1 is shown in a cross-sectional view, where the sample extraction needle 3 is removed from the rest of the handheld device 1. Here the side opening 5 into the tissue sample chamber 26 can be observed. When a tissue sample 27 has been extracted by the handheld device, the sample extraction needle 3 can be removed as shown, and the tissue sample 27 can be removed, before the sample extraction needle 3 is inserted back into the handheld device 1, or, alternatively a new sample extraction needle 3 is inserted. This removal and reuse of the sample extraction needle 3 may be performed while the remaining cutting needle 4 remained inserted in the tissue 30. Thereby, multiple samples may be taken while only penetrating the skin once. In other words the handheld device is a single insertion, multiple samples device. Furthermore, a through-hole 31 can be seen in the cutting needle 4 and a slit 32 in the sample extraction needle 3. The through-hole 31 and slit 32 facilitate together fluid communication from the vacuum chamber 24 to the sample extraction needle 3.

Now, on FIGS. 7A and 7B the extraction of a tissue sample 27 from the tissue 30 is illustrated. The needle arrangement 25 which is inserted into tissue 30 is seen in a cross-sectional view. On FIG. 7A, the cutting needle 4 has moved to exposed the side opening 5 of the sample extraction needle 3, thereby allowing tissue 30 to extend through this side opening 5 and into the tissue sample chamber 26. Furthermore, since the vacuum chamber 24 is in fluid communication with the sample extraction needle 3, the tissue 30 is sucked into the tissue sample chamber 26 due to this vacuum. Then the cutting needle 4 moves over the side opening 5 to a position illustrated on FIG. 7B, thereby cutting a tissue sample 26 from the tissue 30.

Finally, on FIG. 8 illustrates pin control arrangements according to an embodiment of the invention. Here a first pin control arrangement 33 is shown connecting the first and third pins 12, 14. Also, a second pin control arrangement 34 is shown connecting the second and fourth pins 13, 15. The first and second pin control arrangements 33, 34 controls the action of the pins 12, 13, 14, 15, so that pressing the first and second pins 12, 13 to the right by a movement to the right of said second member causes the third and fourth pins 14, 15 to release the first member, causing this first member to move left. In other words, the pin control arrangements 33, 34 control the timing of the releasing of the first and second members to move according to the embodiments described in relation to FIGS. 1-7.

The invention has been exemplified above. However, it should be understood that the invention is not limited to the particular examples described above but may be designed and altered in a multitude of varieties within the scope of the invention as specified in the claims.

According to the present invention the embodiments mentioned in the specification of this patent application may be combined to obtain further embodiments according to the present invention.

LIST OF REFERENCE NUMERALS

-   1. Handheld device -   2. Control arrangement -   3. Sample extraction needle -   4. Cutting needle -   5. Side opening -   6. First spring -   7. Second spring -   8. Cylinder -   9. Piston -   10. Beveled needle end -   11. Oscillation control arrangement -   12. First pin -   13. Second pin -   14. Third pin -   15. Fourth pin -   16. First connection arrangement -   17. Start button -   18. Ring -   19. Sample extraction needle handle -   20. Oscillation ridge -   21. First protrusion -   22. Second protrusion -   23. Cutting edge -   24. Vacuum chamber -   25. Needle arrangement -   26. Tissue sample chamber -   27. Tissue sample -   28. First end -   29. Longitudinal axis -   30. Tissue -   31. Through-hole -   32. Slit -   33. First pin control arrangement -   34. Second pin control arrangement 

The invention claimed is:
 1. A handheld device (1) for extraction of tissue samples (27), comprising a needle arrangement (25) and control arrangement (2), said needle arrangement (25) comprising a cutting needle (4) and a sample extraction needle (3), said needle arrangement (25) having a first end (28) for inserting into tissue (30), said cutting needle (4) comprising a cutting edge (23) for cutting said tissue sample (27) from said tissue (30), said sample extraction needle (3) comprising a side opening (5) for receiving said tissue (30), wherein said cutting needle (4) and said sample extraction needle (3) are adapted for moving relative to each other in a direction along a longitudinal axis (29) of the needle arrangement (25) from a first relative position to a second relative position, wherein at least a part of said side opening (5) is exposed in said first relative position, wherein said side opening (5) of said sample extraction needle (3) is covered in said second relative position, and wherein said movement from said first relative position to said second relative position comprises an oscillatory rotation of said cutting needle (4) relative to said sample extraction needle (3) about the longitudinal axis (29) of the needle arrangement (25), where said oscillatory rotation comprises at least a first relative rotation and a second relative rotation in opposite rotational directions during said relative movement of the cutting needle (4) and sample extraction needle (3) along the longitudinal axis (29) of the needle arrangement; and an oscillation control arrangement (11), wherein the oscillation control arrangement (11) comprises a protruding ridge (20) that extends overall in a direction of the longitudinal axis (29) but also rotates around the longitudinal axis (29) back and forth along the direction of the longitudinal axis (29), and wherein the oscillation control arrangement is configured such that when the oscillation control arrangement (11) moves in a direction along the longitudinal axis (29), the protruding ridge (20) moves through a slit formed by a first protrusion (21) and a second protrusion (22), such that, during this movement, the first and second protrusions (21), (22) force the oscillation control arrangement (11) to rotate about the longitudinal axis (29), thereby facilitating the oscillatory rotation of the cutting needle (4), when the oscillation control arrangement (11) moves in a direction along the longitudinal axis (29) of the needle arrangement (25) due to the cutting needle (4) being connected and fixated to the oscillation control arrangement (11).
 2. A handheld device (1) according to claim 1, wherein a net sum of the first and second relative rotations is less than 360 degree.
 3. A handheld device (1) according to claim 1, wherein the cutting needle (4) is an outer needle surrounding the sample extraction needle (3) being an inner needle.
 4. A handheld device (1) according to claim 1, further comprising: a vacuum chamber (24) in fluid communication with said sample extraction needle (3), the vacuum chamber (24) comprising a first member (8) and a second member (9) adapted to move relative to each other, wherein the first member (8) or the second member (9) is mechanically connected to said cutting needle (4), and wherein said handheld device (1) is configured so that a movement between said first member (8) and said second member (9) to increase the volume of said vacuum chamber (24) thereby reducing the pressure in said sample extraction needle (3) induces a movement between said cutting needle (4) and said sample extraction needle (3) to expose said side opening (5) of said sample extraction needle (3).
 5. A handheld device (1) according to claim 4, wherein said first member is a piston and said second member is a cylinder; or wherein said first member is a cylinder and said second member is a piston.
 6. A handheld device (1) according to claim 4, wherein said movement between said first member (8) and said second member (9) to increase the volume of said vacuum chamber (24) is in a direction along the longitudinal axis (29) of the needle arrangement (25).
 7. A handheld device (1) according to claim 4, wherein said first member (8) is fixated to said cutting needle (4).
 8. A handheld device (1) according to claim 4, wherein the vacuum chamber (24) surrounds at least a part of said needle arrangement (25).
 9. A handheld device (1) according to claim 8, wherein the vacuum chamber (24) is centered about the longitudinal axis (29) of the needle arrangement (25).
 10. A handheld device (1) according to claim 4, wherein the relative movement of said first and second members (8, 9) are driven by a second driving arrangement.
 11. A handheld device (1) according to claim 10, wherein said second driving arrangement comprise a second spring (7).
 12. A handheld device (1) according to claim 4, wherein said second member is adapted to perform a movement along the longitudinal axis (29) of the needle arrangement (25) towards the first end (28) of the needle arrangement (25) thereby increasing the volume of the vacuum chamber (24) and building up a vacuum before the side opening (5) is exposed.
 13. A handheld device (1) according to claim 10, wherein said handheld device (1) comprises first driving arrangement for driving a movement of said second member (9) along the longitudinal axis (29) of the needle arrangement (25) towards the first end of the needle arrangement (25).
 14. A handheld device (1) according to claim 13, wherein said first driving arrangement comprise a first spring (6).
 15. A handheld device (1) according to claim 4, wherein said first and second members are adapted to move together in a direction along the longitudinal axis (29) of the needle arrangement (25) in a direction towards the first end (28) of the needle arrangement (25) while being substantially stationary relative to each other, wherein said cutting needle (4) connected to said first member and said sample extraction needle (3) are adapted for moving relative to each other along the longitudinal axis (29) of said needle arrangement (25) from a first to a second relative position, wherein at least a part of said side opening (5) is exposed in said first relative position, and wherein said side opening (5) of said sample extraction needle (3) is substantially covered in said second relative position, thereby cutting said tissue sample (27) from said tissue (30).
 16. A handheld device (1) according to claim 13, wherein the control arrangement (2) furthermore comprises a charging arrangement for charging said first and second driving arrangements.
 17. A handheld device (1) according to claim 1, wherein the sample extraction needle (3) may be removed from the rest of the handheld device (1) so as to remove extracted tissue samples (27). 